"Meton of Athens Meton of Athens (; ""gen"".: Μέτωνος) was a Greek mathematician, astronomer, geometer, and engineer who lived in Athens in the 5th century BC. He is best known for calculations involving the eponymous 19-year Metonic cycle which he introduced in 432 BC into the lunisolar Attic calendar. The metonic calendar incorporates knowledge that 19 solar years and 235 lunar months are very near equal, thus lunar periods often, but not unconditionally, repeat on the same day of the year as 19 years previous. This system was based on calculations made by Meton using his own observations of the"
"shows that: This gives an error of only about half an hour in 687 years (2.5 seconds a year), although this is subject to secular variation in the length of the tropical year and the lunation. Meton of Athens approximated the cycle to a whole number (6,940) of days, obtained by 125 long months of 30 days and 110 short months of 29 days. During the next century, Callippus developed the Callippic cycle of four 19-year periods for a 76-year cycle with a mean year of exactly 365.25 days. Metonic cycle For astronomy and calendar studies, the Metonic cycle or"
"that the Metonic cycle may have been learned by the Greeks from Babylonian scribes. Meton of Athens, a Greek astronomer of the 5th century BCE, developed a lunisolar calendar based on the fact that 19 solar years is about equal to 235 lunar months, a period relation that perhaps was also known to the Babylonians. In the 4th century BCE, Eudoxus of Cnidus wrote a book on the fixed stars. His descriptions of many constellations, especially the twelve signs of the zodiac show similarities to Babylonian. The following century Aristarchus of Samos used an eclipse cycle called the Saros cycle"
"Circannual cycle A circannual cycle is a biological process that occurs in living creatures over the period of approximately one year. This cycle was first discovered by Ebo Gwinner and Canadian biologist Ted Pengelley. It is classified as an Infradian rhythm, which is biological process with a period longer than that of a circadian rhythm, less than one cycle per 28 hours. These processes continue even in artificial environments in which seasonal cues have been removed by scientists. The term circannual is Latin, circa meaning approximately and annual relating to one year. Chronobiology is the field of biology pertaining to"
"of a scientist makes this branch of chronobiology difficult. It takes an entire year to get a time series which makes it difficult to see how these cycles adjust over the years. To put this into perspective, a two-week experiment for a circadian biologist would take fourteen years for a circannual researcher, in order to achieve the same level of data robustness for the conclusions. Circannual cycle A circannual cycle is a biological process that occurs in living creatures over the period of approximately one year. This cycle was first discovered by Ebo Gwinner and Canadian biologist Ted Pengelley. It"
"Metonic cycles (76 years) for an average year of 365+1/4 or 365.25 days. Hipparchus dropped one more day from four Callippic cycles (304 years), creating the Hipparchic cycle with an average year of 365+1/4−1/304 or 365.24671 days, which was close to his tropical year of 365+1/4−1/300 or 365.24667 days. We find Hipparchus's mathematical signatures in the Antikythera Mechanism, an ancient astronomical computer of the second century BC. The mechanism is based on a solar year, the Metonic Cycle, which is the period the Moon reappears in the same place in the sky with the same phase (full Moon appears at"
"the occurrence of leap years. It is set at the beginning of each year by observing the first full moon after the winter solstice. The oldest one known, and the only one from the Middle Ages, is the Nyköping staff, which is believed to date from the 13th century. The Bahá'í calendar, established during the middle of the 19th century, is also based on cycles of 19 years. The Metonic cycle is related to two less accurate subcycles: By combining appropriate numbers of 11-year and 19-year periods, it is possible to generate ever more accurate cycles. For example, simple arithmetic"
"seems quite muddied. Also, where Metcalf and Allen saw periods of two and six in their spectral plots, there is room for alternative interpretations. All of this ambiguity necessitate some serpentine, post-hoc explanation to show that results fit a chaotic model. By adapting a model of career counseling to include a chaotic interpretation of the relationship between employees and the job market, Aniundson and Bright found that better suggestions can be made to people struggling with career decisions. Modern organizations are increasingly seen as open complex adaptive systems with fundamental natural nonlinear structures, subject to internal and external forces that"
"three centuries. The epacts for the current Metonic cycle, which began in 2014, are: The above table is valid from 1900 to 2199 inclusive. As an example of use, the golden number for 2038 is 6 (; ). From the table, paschal full moon for golden number 6 is 18 April. From week table 18 April is Sunday. Easter Sunday is the following Sunday, 25 April. The epacts are used to find the dates of the new moon in the following way: Write down a table of all 365 days of the year (the leap day is ignored). Then label"
"The Metonic cycle is equal to one Saros cycle plus one lunar year, and so the two series progress in parallel. The Inex cycle (29 years minus 20 days) can last tens of thousands of years, so long that long perturbations in the moon's path must be taken into account for prediction. Also the eclipse qualities are less inconsistent because the moon is at different significantly positions in its elliptical orbit in sequential events. Similarly for the shorter Tritos cycle (10 years and 31 days), repeats less consistently for same reason. This eclipse is the third of four lunar year"
"based on the tropical year and maintain the seasons at the same calendar times each year. Nineteen tropical years are about two hours shorter than 235 synodic months. The Metonic cycle's error is, therefore, one full day every 219 years, or 12.4 parts per million. Note that the 19-year cycle is also close (to somewhat more than half a day) to 255 draconic months, so it is also an eclipse cycle, which lasts only for about 4 or 5 recurrences of eclipses. The Octon is of a Metonic cycle (47 synodic months, 3.8 years), and it recurs about 20 to"
"represent information and allocate mental functions to brain networks (such as metabolic activity and cortical specialization and pruning) may occur mainly at the early phase of each cycle that are associated with an increase in the speed-intelligence relations (2–3, 6–7, and 11–13 years). Changes in connectivity that may relate to mapping concepts onto each other and meta-represent them into new concepts occur at second phase of each cycle associated with an increase in the working memory–intelligence relations. In recent years, there has been an increasing interest in theories and methods that show promise for capturing and modeling the regularities underlying"
"days. The Metonic train is driven by the drive train b1, b2, l1, l2, m1, m2, and n1, which is connected to the pointer. The modelled rotational period of the pointer is the length of the 6939.5 days (over the whole five-rotation spiral), while the modern value for the Metonic cycle is 6939.69 days. The Olympiad train is driven by b1, b2, l1, l2, m1, m2, n1, n2, and o1, which mounts the pointer. It has a computed modelled rotational period of exactly 4 years, as expected. Incidentally, it is the only pointer on the mechanism that rotates counter-clockwise; all"
"with test scores. When completing empathy exercises, women in the follicular stage of their menstrual cycle performed better than women in their midluteal phase. A significant correlation between progesterone levels and the ability to accurately recognize emotion was found. Performances on emotion recognition tasks were better when women had lower progesterone levels. Women in the follicular stage showed higher emotion recognition accuracy than their midluteal phase counterparts. Women were found to react more to negative stimuli when in midluteal stage over the women in the follicular stage, perhaps indicating more reactivity to social stress during that menstrual cycle phase. Overall,"
"mitochondrion. The overall yield of energy-containing compounds from the TCA cycle is three NADH, one FAD(2H), and one GTP. Several of the components and reactions of the citric acid cycle were established in the 1830s by the research of Albert Szent-Györgyi, who received the Nobel Prize in Physiology or Medicine in 1937 specifically for his discoveries pertaining to fumaric acid, a key component of the cycle. He was able to make this discovery successful with the help of pigeon breast muscle. Because this tissue maintains its oxidative capacity well after breaking down in the ""Latapie"" mill and releasing in aqueous"
"also obtained, allowing a new gearing scheme to be advanced. This more accurate information allowed Wright to confirm Price's perceptive suggestion that the upper back dial displays the Metonic cycle with 235 lunar months divisions over a five-turn scale. In addition to this Wright proposed the remarkable idea that the main back dials are in the form of spirals, with the upper back dial out as a five-turn spiral containing 47 divisions in each turn. It therefore presented a visual display of the 235 months of the Metonic cycle (19 years ≈ 235 Synodic Months). Wright also observed that fragmentary"
"involved calculating daily stepwise changes of lunar speed, up or down, with a minimum and a maximum approximately each month. The basis of these systems appears to have been arithmetical rather than geometrical, but they did approximately account for the main lunar inequality now known as the equation of the center. The Babylonians kept very accurate records for hundreds of years of new moons and eclipses. Some time between the years 500 BC and 400 BC they identified and began to use the 19 year cyclic relation between lunar months and solar years now known as the Metonic cycle. This"
"Metaphase Metaphase (from the Greek μετά, ""adjacent"" and φάσις, ""stage"") is a stage of mitosis in the eukaryotic cell cycle in which chromosomes are at their second-most condensed and coiled stage (they are at their most condensed in anaphase). These chromosomes, carrying genetic information, align in the equator of the cell before being separated into each of the two daughter cells. Metaphase accounts for approximately 4% of the cell cycle's duration. Preceded by events in prometaphase and followed by anaphase, microtubules formed in prophase have already found and attached themselves to kinetochores in metaphase. In metaphase, the centromeres of the"
"response to the cycles in end users markets such as that in freight rates. He further suggests that the cycle length of the upstream industry is four times the lag, and is about 17 years in the shipbuilding industry. Besides the traditional industries, many new industries such as semiconductors, flat panel displays, computers and telecommunications also exhibit strong cyclicality. In the service sector, for example, Choi and colleagues date the industry cycles of the US hotel industry and restaurant industry. They establish the mean duration of the business cycle, measured with aggregate activities in absolute level, as about 7.3 years"
"should be noted that economic cycle theories have enabled some analysts to correctly predict the timing of recessions, stock market peaks and stock market crashes over the past couple of decades."" The historian Eric Hobsbawm also wrote of the theory: ""That good predictions have proved possible on the basis of Kondratiev Long Waves—this is not very common in economics—has convinced many historians and even some economists that there is something in them, even if we don't know what.” Kondratiev identified three phases in the cycle: expansion, stagnation, and recession. More common today is the division into four periods with a"
"Metadynamics Metadynamics (MTD; also abbreviated as METAD or MetaD) is a computer simulation method in computational physics, chemistry and biology. It is used to estimate the free energy and other state functions of a system, where ergodicity is hindered by the form of the system's energy landscape. It was first suggested by Alessandro Laio and Michele Parrinello in 2002 and is usually applied within molecular dynamics simulations. MTD closely resembles a number of recent methods such as adaptively biased molecular dynamics, adaptive reaction coordinate forces and local elevation umbrella sampling. More recently, both the original and well-tempered metadynamics were derived"
"acceptable level of statistical significance. Korotayev & Tsirel also detected shorter business cycles, dating the Kuznets to about 17 years and calling it the third sub-harmonic of the Kondratiev, meaning that there are three Kuznets cycles per Kondratiev. In recent years economic theory has moved towards the study of ""economic fluctuation"" rather than a 'business cycle' – though some economists use the phrase 'business cycle' as a convenient shorthand. For example, Milton Friedman said that calling the business cycle a ""cycle"" is a misnomer, because of its non-cyclical nature. Friedman believed that for the most part, excluding very large supply"
"of the intercalation from as early as 2000 BC, about the time of the biblical Tower of Babel, the confusion of language, and dispersion of nations. Whether or not the correlation indicates cause-and-effect relationship is an open question. The Greek astronomer Meton in the fifth century BC discovered the same principle, and the western civilization named the cycle after him. The west later applied the Metonic cycle on the solar Roman years (Julian and Gregorian years) in the Era of the Lord (Anno Domini), a.k.a. the Common Era. The golden number is the remaining number of dividing the year in"
"of the other competitors, all of whom are looking at the problem from the same point of view. It is not a case of choosing those which, to the best of one's judgment, are really the prettiest, nor even those which average opinion genuinely thinks the prettiest. We have reached the third degree where we devote our intelligences to anticipating what average opinion expects the average opinion to be. And there are some, I believe, who practise the fourth, fifth and higher degrees. Keynes's theory of the trade cycle is a theory of the slow oscillation of money income which"
"cycles that affect his or her ability in various domains, such as mental, physical and emotional activity. These cycles begin at birth and oscillate in a steady (sine wave) fashion throughout life, and by modeling them mathematically, it is suggested that a person's level of ability in each of these domains can be predicted from day to day. The theory is built on the idea that the biofeedback chemical and hormonal secretion functions within the body could show a sinusoidal behavior over time. Most biorhythm models use three cycles: a 23-day physical cycle, a 28-day emotional cycle, and a 33-day"
"and trends. In his spare time, he studies cycles. Human behavior seems to run in cycles, with prices, wages, hemlines, fashions, and entire economies crashing and rising again for no reason, except that each was following the ups and downs of a cycle. Three big cycles bottomed out in 1929, causing the Crash of 1929. It is now 1952, and every cycle he tracks will either trough or crest simultaneously in about six months. Breen explains to Meade Barstow, the young lady, that ""This year, the human race is letting down its hair, flipping its lip with a finger, and"
"Kitchin cycle Kitchin cycle is a short business cycle of about 40 months discovered in the 1920s by Joseph Kitchin. This cycle is believed to be accounted for by time lags in information movements affecting the decision making of commercial firms. Firms react to the improvement of commercial situation through the increase in output through the full employment of the extent fixed capital assets. As a result, within a certain period of time (ranging between a few months and two years) the market gets ‘flooded’ with commodities whose quantity becomes gradually excessive. The demand declines, prices drop, the produced commodities"
"in mainstream economics and in the heterodox school of post-Keynesian economics, and has subsequently been developed by such post-Keynesian economists as Hyman Minsky and Steve Keen. Inequity appears to be the most obvious driver of Kondratiev waves, and yet some researches have presented a technological and credit cycle explanation as well. There are several modern timing versions of the cycle although most are based on either of two causes: one on technology and the other on the credit cycle. Additionally, there are several versions of the technological cycles, and they are best interpreted using diffusion curves of leading industries. For"
"of the sun from which they had started."" As ""the twentieth year"" takes place nineteen years after ""the first year"", this seems to indicate that the Metonic cycle was applied to Numa's calendar. Apollo was said to have visited the Hyperboreans once every 19 years, presumably at the high point of the cycle. The Runic calendar is a perpetual calendar based on the 19-year-long Metonic cycle. Also known as a Rune staff or Runic Almanac, it appears to have been a medieval Swedish invention. This calendar does not rely on knowledge of the duration of the tropical year or of"
"Mechanobiology Mechanobiology is an emerging field of science at the interface of biology and engineering that focuses on how physical forces and changes in the mechanical properties of cells and tissues contribute to development, cell differentiation, physiology, and disease. A major challenge in the field is understanding mechanotransduction—the molecular mechanisms by which cells sense and respond to mechanical signals. While medicine has typically looked for the genetic and biochemical basis of disease, advances in mechanobiology suggest that changes in cell mechanics, extracellular matrix structure, or mechanotransduction may contribute to the development of many diseases, including atherosclerosis, fibrosis, asthma, osteoporosis, heart"
"13 cycles was used to realign the lunar and solar years. The extra month was achieved by repeating an existing month so the same month name was used twice in a row. Handbooks usually refer to the sixth month, Poseideon, as the month that was repeated, but months 1, 2, 6, 7 and 8 are all attested as being doubled (Hannah 2005: 43). Various cycles were in existence for working out exactly which years needed to add a thirteenth month. A nineteen-year cycle, the Metonic cycle, developed at Athens by the astronomers Meton and Euctemon (known to be active in"
"Callippic cycle For astronomy and calendar studies, the Callippic cycle (or Calippic) is a particular approximate common multiple of the year (specifically the tropical year) and the synodic month, that was proposed by Callippus during 330 BC. It is a period of 76 years, as an improvement of the 19-year Metonic cycle. A century before Callippus, Meton had discovered the cycle in which 19 years equals 235 lunations. If we assume a year is about days, 19 years total about 6940 days, which exceeds 235 lunations by almost a third of a day, and 19 tropical years by four tenths"
"only 22% of messenger RNA cycling genes are driven by de novo transcription. RNA-level post-transcriptional mechanisms driving rhythmic protein expression were later reported, such as mRNA polyadenylation dynamics. Fustin and co-workers identified methylation of internal adenosines (mA) within mRNA (notably of clock transcripts themselves) as a key regulator of the circadian period. Inhibition of mA methylation via pharmacological inhibition of cellular methylations or more specifically by siRNA-mediated silencing of the mA methylase ""Mettl3"" led to the dramatic elongation of the circadian period. In contrast, overexpression of ""Mettl3"" ""in vitro"" led to a shorter period. These observations clearly demonstrated the importance"